In the semiconductor process, chemical mechanical planarization (CMP) is used as a surface polishing process for forming highly integrated multilayer structured devices. As the pattern size of semiconductors gradually decreases, the importance of the polishing process in the manufacture of patterns is gradually increasing. In a process for manufacturing a semiconductor device, single crystal silicon wafers, which are capable of making initial material at a low cost and making an oxide film with excellent electrical insulation properties, are used as a main material. In the semiconductor process, surface roughness of the silicon wafer has a great influence on subsequent processes, and thus performance of planarization using the CMP process is essential. Polycrystalline silicon thin film is used in processes for manufacturing integrated chips (ICs), recess channel array transistors (RCATs), and 3D Fin Field-effect transistors (FinFET), and thus there is a need for research on minimization of the surface roughness using the CMP process.
Polishing compositions may be used for polishing silicon materials, i.e., silicon groups such as silicon single crystal, amorphous silicon, polysilicon, and the like, and silicon compounds such as silicon nitride, and silicon oxide. More specifically, for example, polishing compositions are mainly used for polishing silicon substrates such as single crystal silicon substrates, or the like; or for polishing silicon group films such as amorphous silicon films, polycrystalline silicon films, or the like, or silicon compounds such as silicon nitride, silicon oxide, or the like, formed on the silicon substrate. Silicon compound films include low-k films with a relative permittivity of 3 or less. In low-k films, the polishing selectivity and polishing speed are key points for the semiconductor polishing process. Thus, there is a need for studies on a polishing slurry composition with a high polishing speed and various polishing selectivities.
Therefore, the present inventors studied compositions for polishing a polycrystalline silicon film, found that when a compound including a thio group or a thiol group was used and added as an additive in a polycrystalline silicon polishing composition including a polishing agent it was possible to prepare a polishing slurry composition with an improved polishing speed and various polishing selectivities, and thus completed the present invention.